Quote from: heavyarms

Some don't clock as high as others do. I have couple of cards that don't go above 1950 without causing lots of memory errors and eventually crashing.
The core on these cards need higher voltage and the cooler isn't good on these cards either which makes it even worse for stability. Both cards are from same batch so it might be just that.

MSI Armor RX470?
I really don't like the construction. Appears to be a board with 5cm of useless PCB just to make it bigger. Without it, the size would be compatible with a RX460.

Quote from: QuirkSilver on July 25, 2018, 05:30:25 PM

Quote from: Larvitar on July 25, 2018, 11:27:07 AM

Quote from: Branko on July 25, 2018, 07:39:43 AM

Same as mine that goes up to 2300...but to go that high, cooling should be made
in such way that metal plate covers not only GPU, but memory, too (and replacing
usually bad factory thermal paste with quality one)

However, 2100 should be easy to achieve

Also, important is to find sweet spot between voltage and temperature (voltage increase
improves stability, but only up to the point where increased heat starts to be a problem)

I bought it from a miner, so it came with some thermalpads and a good biosmod, but not all ICs are cooled (only 5/8) because the other three arent in the cooler contact area. I ordered some heatsinks at Aliexpress but it will take a little time to arrive (3 months. Yeah, Brazil's mail is poor).

About the memory strap: The board came to me with Matthev timing. I tried many timings (heavyarms, yours, some for anorak's) and the original one (matthev) was best (at least at 1900~2000 clocks). I did some changes/tests and for now I have it:
777000000000000022CC1C00CE615C41C0571016B30CD50900400700140514207A8900A00300000 010122F3F9D2C3617

Is there a way to improve "performance per clock" for Cryptonight? (considering that it couldn't run at 2000+)

i do use thermal pads (these are quite good) https://www.aliexpress.com/item/ARSYLID-High-quality-100-200-1-0-2-0-4-5mm-Thermal-conductivity-3-6W-CPU/32835108024.html?spm=a2g0s.9042311.0.0.4fd54c4d3E82Yb
0.5 mm or 1 mm and a copper shim, 1 mm thick or more https://www.aliexpress.com/item/20-pcs-15mmx15mm-0-3mm-0-4mm-0-5mm-0-6mm-0-8mm-1mm-Heatsink-Copper/32826278552.html?spm=a2g0s.9042311.0.0.3dbd4c4dpaqYyI
I experiment with the thicknesses so that the stock heatsink presses the shim and the pad slightly without being thicker than the processor height (been there done that, and the GPU fan was squealing

) the more spacious the copper shims the better, however, i do this on rough estimates, that the memory die consumes 1-2 watts each (reasonable?) the shims not touching the aluminum directly is not a big problem, because copper blown by the gpu fan imho is more than sufficient to cool the memory. Most of the Aorus 580s i have memory cooled from the factory reach 2100-2200mhz (8 gb, 4gb all of them hynix) i found thermal pads being 0.5 mm and perfectly matched with the heatsink, but, as a consequence of mining these pads will dry within months (become brittle)

Do you really clock those elpidas to these clocks? lol? how do you cool them? what sort of timings for such clocks!?

Isn't Elpida memories, but Micron. Micron sometimes can be overclocked above 2100 (Branko's 560 can handle this)

I bought these ones (0.5mm): https://www.aliexpress.com/item/20-pcs-15mmx15mm-0-3mm-0-4mm-0-5mm-0-6mm-0-8mm-1mm-Heatsink-Copper/32826278552.html?spm=a2g0s.9042311.0.0.5311b90arAsvdv
And these thermalpads: https://www.aliexpress.com/item/2016-high-quality-10mm-10mm-1mm-100-pcs-Thermal-Pad-GPU-CPU-Heatsink-Cooling-Conductive-Silicone/32675801589.html?spm=a2g0s.9042311.0.0.5311b90arAsvdv

Quote from: QuirkSilver

2- tCR of the stock strap, needs to be loosened, its tied to tCL, tRCDR,tRP, tRRD are tied to tCR (not tRP in elpida, thats why you can have a very low tCR value) so any +1/-1 to any of those, must be subsequently, done tCR value.
example,
tcrdr 23, tRRD 7,tCL 18, tRP 22 tCR=68
trcdr 24 (+1), tRRD 6 (-1), tCL 18, tRP 22 tCR= (68)

tCR=68 should be tRC?

Here I'm with this:
TCRDR(A) 24, tRRD 6, tCL 22, tRP 20, tRC 65 (tried to low tCL to 20, but didn't worked)
24 + 5 + 22 + 20 = 71. So I would have to bump tRC to 71?

Quote from: QuirkSilver

3-RASMACTRD,RASMACTWR are tied to ACTRD and ACTWR by the rule, RASMACTRD(/W) + ACTRD(/W)= tCR+1 (check any stock strap, same thing) so when you drop writes (-actwr) you should increase RASMACTWR

Yep, I see some gains by loosening RASMACTWR.
870H/s at 50
917H/s at 63
921H/s at 66

But the formula you gave didn't fit here (or I dont understood):
ACTWR (18) + best RASMACTWR (66) = 84
tRC (65) + 1 = 66

Quote from: QuirkSilver

4- Raw Precharge time, tRP must be higher than tCL, it doesnt affect Cryptonight much so its one of the keys to attain high stable straps (by loosening it)
5-loosening tCL is the key to get a higher strap, but now that's the biggest problem, tCL in elpida isn't tied to tCR (that's why you see that one click strap, being good with a low tRC), however, CAS timings (tCL,W2R,R2W) are linked to SEQ-MISC-1
If you changed the tCL of the 1625 strap to the 1750 one without the SEQ-MISC-1 of the 1750 one, will end in BSODs or similar.
Micron one click, took, Elpida's 1500mhz strap and mixed it, so higher tCL mainly, and that works..

Nice!
tRP is at 20, tCL at 22. So I will try it at 22 or 23.

The 5th tip is intersting. Maybe the issue with tCL at 20 (I tried it today) can be linked with it. I will see the strap and find where tCL 20 are, and copy SEC-MISC-1.

Quote from: QuirkSilver

6-increase tRFC substantially, have minimal impact on CN speeds, but gives more stability (+25% or whatever, noticed no real rules here.)

tRFC is a controverse timing. It gives pain while overclocking memories since DDR2 ;p

About looseining it: considering I can't go above 2000 for while (maybe because memory cooling, maybe because the shitty ICs) lowering tRFC (from 157 to 129) was a solution to gain some hashes (around 10H/s at 1900).

Quote from: Branko

Micron and micron-elpida are quite a different story, both in timings and max clock.

Also, your estimate about memory chips power consumption is way too low,

"RX 480 uses 40-50W for its 8GB"

Source:

https://www.gamersnexus.net/guides/3032-vega-56-cost-of-hbm2-and-necessity-to-use-it

So for 8GB cards almost half the consumption goes to memory chips

Holy feijoada!

I don't understand why it comes to us without proper cooling, because it needs. Unafortunately lowering voltage needs hardware mods (could help sometimes).

I really want to thank you three for all knowledge! You are awesome!